Clostridium perfringens (CP), which is gram-positive large obligatory anaerobic bacillus, has been known as a bacterium that does not have flagellum and forms a spore. Clostridium perfringens, which is a bacterium causing diarrhea, or the like, particularly, in domestic animals such as chicken, pig, etc., and the like, has been recognized as one of the important and fatal pathogenic bacteria in a livestock industry, as well as Salmonella causing fowl typhoid.
Currently, one of the diseases frequently generated in poultry and pork industries is Necrotic Enteritis by Clostridium perfringens. It is known that Necrotic Enteritis is frequently generated by co-infection of Clostridium perfringens and Coccidium, and as a main symptom of necrotic enteritis, there is bloody diarrhea due to severe necrotic lesions in a lower portion of small intestine of chickens, swines, or the like.
This necrotic enteritis generates dehydration symptom, periodic diarrhea, and the like, in an infected animal according to the disease severity, gradually debilitates a body of the animal, and causes growth retardation, and the like, such that necrotic enteritis has become a significant problem in the livestock industry. Further, since Clostridium perfringens is easily propagated through feces of animal, transmission between animals in a common breeding space may be easily generated by oral infection through soil or contaminated feed, or the like. Particularly, incidence in young animal is high, such that Clostridium perfringens has become a problem.
Meanwhile, bacteriophage is a specialized type of virus that infects and destroys only bacteria, and can self-replicate only inside host bacteria. The bacteriophage has strong host specificity as compared to antibiotics, and recently, a problem of emergence of strain resistant against antibiotics has become serious, such that an interest in practical use of the bacteriophage has increased (Non-Patent Documents 1 and 2).
Therefore, research concerning the bacteriophage has been actively conducted in various countries around the world, and in addition to a patent application for bacteriophage, an attempt to acquire Food and Drug Administration (FDA) approval for a composition containing the bacteriophage has been gradually increased.
As the prior art documents concerning the bacteriophage, a bacteriophage having a specific bactericidal activity against Clostridium perfringens has been disclosed in Patent Document 1, and a bacteriophage having a specific bactericidal activity against Staphylococcus aureus has been disclosed in Patent Document 2. Further, lytic protein derived from a bacteriophage specifically destroying peptidoglycan structure of bacterial cell membrane, and bacteria lysates by the lytic protein have been disclosed in Patent Document 3.
However, in spite of presence of the following prior arts, a technology associated with the bacteriophage for preventing and/or treating infectious diseases, particularly, necrotic enteritis by Clostridium perfringens that is a still important problem in the livestock industry including poultry and pork industries is still insufficient, such that a bacteriophage and a technology associated with the bacteriophage should be developed.